Structure-function relationship studies with human fibroblast (F) interferon and human leukocyte (Le) interferon will be continued, with specific emphasis on the role of carbohydrate moiety in physicochemical properties, antigenicity and biological activities. Methods will be developed for the production and purification of human immune (type II) interferon. Purified Le, F and immune interferons will be compared in their biological activities including antiviral action in homospecific and heterospecific cells, growth inhibitory action in normal and tumor cells, and various immunoregulatory activities. The kinetics of interferon production and the type of interferon produced (F, Le or immune) will be determined in serum samples from patients with various forms of measles virus infection and in vesicular fluid samples from patients infected with varicella-zoster virus.